Display device

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2017-0066264 filed in the Korean Intellectual Property Office on May 29, 2017, the disclosure of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

One or more exemplary embodiments of the present invention relates to a display device, and more particularly, to a foldable display device.

DISCUSSION OF THE RELATED ART

A flexible display panel is a display panel in which a plurality of pixels is disposed on a flexible substrate such as a plastic film. Foldable display devices may include a flexible display panel and a foldable module that can be folded and unfolded.

However, when the flexible display panel uses a thin glass sheet as a cover window, but it may not be freely folded due to high bending stiffness, for example.

SUMMARY

According to an exemplary embodiment of the present invention, a display device, includes a display panel including a first region, a bendable region, and a second region arranged in sequence. The display device further includes a panel support unit including a first support plate for supporting the first region, a form varying support unit for supporting the bendable region, and a second support plate for supporting the second region. The display device additionally includes an elastic support unit including a first guide line provided on a lateral side of the first support plate, a second guide line provided on a lateral side of the second support plate, a first rolling member rotatably coupled to the first guide line, a second rolling member rotabably coupled to the second guide line, and an elastic body including a first end portion fixed to the first rolling member and a second end portion fixed to the second rolling member.

According to an exemplary embodiment of the present invention, the display device includes a display panel including a first region, a bendable region, and a second region consecutively arranged in a first direction. The display device further includes a panel support unit including a first support plate corresponding to the first region, a form varying support unit corresponding to the bendable region, and a second support plate corresponding to the second region. The panel support unit is configured to switch between an unfolded state and a folded state by a movement of the bendable region and the form varying support unit. The display device additionally includes an elastic body including a first end portion connected with a first rolling member configured to slide and rotate in the first direction on a lateral side of the first support plate and a second end portion connected with a second rolling member configured to slide and rotate in the first direction on a lateral side of the second support plate. The elastic body is connected to the first support plate and the second support plate. The elastic body extends to a first length in the unfolded state, and when switching to the folded state from the unfolded state, the first support plate and the second support plate are pulled toward each other by contraction of the elastic body.

According to an exemplary embodiment of the present invention, the display device includes a flexible display panel including a first region, a second region and a flexible region disposed between the first region and the second region. The display device further includes a panel support structure including a first support plate overlapping the first region, a form varying support unit overlapping the flexible region and including a plurality of joints, and a second support plate overlapping the second region. The display device additionally includes an elastic support unit including a first guide line, a second guide line, a first rolling member and a second rolling member respectively disposed in the first guide line and in the second guide line, and an elastic body connected to the first and second rolling members. The first guide line is provided in a lateral side of the first support plate and the second guide line is provided in a lateral side of the second support plate, and the first and second rolling members respectively travel inside of the first and second guide lines.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof, with reference to the accompanying drawings, in which:

<figref idref="DRAWINGS">FIG. 1</figref> shows a perspective view of an unfolded state of a display device according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 2</figref> shows an exploded perspective view of a display device shown in <figref idref="DRAWINGS">FIG. 1</figref> according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 3</figref> shows a partial side view of a display device shown in <figref idref="DRAWINGS">FIG. 1</figref> according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 4</figref> shows a cross-sectional view of a display panel in a display device shown in <figref idref="DRAWINGS">FIG. 3</figref> according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 5</figref> shows a cross-sectional view of a display device with respect to a line V-V of <figref idref="DRAWINGS">FIG. 1</figref> according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 6</figref> shows a partial perspective view of an elastic support unit in a display device shown in <figref idref="DRAWINGS">FIG. 1</figref> according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 7</figref> shows a side view of a display device while being folded by an out-folding method according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 8</figref> shows a side view of a display device folded by an out-folding method according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 9</figref> shows a side view of a display device while being folded by an in-folding method according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 10</figref> shows a sideview of a display device folded by an in-folding method according to an exemplary embodiment of the present invention.

<figref idref="DRAWINGS">FIG. 11</figref> and <figref idref="DRAWINGS">FIG. 12</figref> show a side view of a folded state of a display device according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings. It will be understood, however, that the described embodiments of the present invention may be modified in various different ways.

Like reference numerals may designate like elements throughout the present disclosure.

It will be understood that the size and thickness of each configuration shown in the drawings may be exaggerated for better understanding and ease of description, but the present invention is not limited thereto.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it may be directly on the other element or intervening elements may also be present.

<figref idref="DRAWINGS">FIG. 1</figref> shows a perspective view of an unfolded state of a display device according to an exemplary embodiment of the present invention, and <figref idref="DRAWINGS">FIG. 2</figref> shows an exploded perspective view of a display device shown in <figref idref="DRAWINGS">FIG. 1</figref> according to an exemplary embodiment of the present invention. <figref idref="DRAWINGS">FIG. 3</figref> shows a partial side view of a display device shown in <figref idref="DRAWINGS">FIG. 1</figref> according to an exemplary embodiment of the present invention, and <figref idref="DRAWINGS">FIG. 4</figref> shows a cross-sectional view of a display panel in a display device shown in <figref idref="DRAWINGS">FIG. 3</figref> according to an exemplary embodiment of the present invention.

Referring to <figref idref="DRAWINGS">FIG. 1</figref> to <figref idref="DRAWINGS">FIG. 4</figref>, the display device <b>100</b> according to an exemplary embodiment of the present invention includes a display panel <b>10</b> and a foldable module <b>20</b>. The foldable module <b>20</b> supports the display panel <b>10</b> and is configured to be switchable to an unfolded state and a folded state.

The display panel <b>10</b> includes a flexible substrate <b>11</b> and a display unit <b>12</b> provided on the flexible substrate <b>11</b>. The flexible substrate <b>11</b> may include a plastic film, and the display unit <b>12</b> may include a plurality of pixels and driving circuits. The display panel <b>10</b> may further include a touch sensor <b>13</b>, an external light reflection reducer <b>14</b>, and a cover window <b>15</b>.

The cover window <b>15</b> is provided on a highest portion of the display panel <b>10</b> to protect the display unit <b>12</b> from external impacts and scratches. For example, the cover window <b>15</b> may form the top surface of the display panel <b>10</b>. The cover window <b>15</b> may be made of a glass sheet that is thin enough to be bent (e.g., about 50 μm to about 100 μm thick).

The display panel <b>10</b> including the cover window <b>15</b> made of a glass sheet may have excellent screen quality. The display panel <b>10</b> may not be freely bent because of the bending stiffness of the glass sheet composing the cover window <b>15</b>. The bending stiffness of the cover window <b>15</b> is proportional to the thickness of the cover window <b>15</b>, and thus, a stress capable of being generated at the cover window <b>15</b> linearly increases as the thickness of the cover window <b>15</b> increases.

The display panel <b>10</b> includes a first region <b>101</b>, a bendable region <b>103</b>, and a second region <b>102</b> consecutively arranged in a first direction (e.g., an X direction). The first region <b>101</b> and the second region <b>102</b> may be flat regions, and may have a same length or different lengths in the first direction (e.g., the X direction). The bendable region <b>103</b> is flat when the display device <b>100</b> is in the unfolded state, and it is bent when the display device <b>100</b> is in the folded state

The display panel <b>10</b> may be an organic light emitting diode display panel, a liquid crystal display panel, or an electrophoretic display panel. However, the present invention it is not limited thereto.

The foldable module <b>20</b> includes a panel support unit <b>30</b> and an elastic support unit <b>40</b>. The panel support unit <b>30</b> is combined with the display panel <b>10</b> to support the display panel <b>10</b>, and the elastic support unit <b>40</b> is combined with the panel support unit <b>30</b> to reduce the bending stiffness of the display panel <b>10</b>.

The panel support unit <b>30</b> includes a first support plate <b>31</b> corresponding to the first region <b>101</b>, a second support plate <b>32</b> corresponding to the second region <b>102</b>, and a form varying support unit <b>33</b> corresponding to the bendable region <b>103</b>. A rear side of the first region <b>101</b> may be attached to the first support plate <b>31</b>, and a rear side of the second region <b>102</b> may be attached to the second support plate <b>32</b>. The first support plate <b>31</b> and the second support plate <b>32</b> may face each other with the form varying support unit <b>33</b> therebetween. The first support plate <b>31</b> and the second support plate <b>32</b> respectively include a pair of lateral sides in parallel to the first direction (e.g., an X direction). For example, the first support plate <b>31</b> may have a pair of sides <b>311</b>, and the second support plate <b>32</b> may have a pair of sides <b>321</b>.

The form varying support unit <b>33</b> may include a multi-joint member. For example, the multi-joint member may include a plurality of joints <b>34</b> consecutively arranged in the first direction (e.g., the X direction). The joints <b>34</b> may have, for example, a bar shape extending in a second direction (e.g., a Y direction) crossing the first direction (e.g., the X direction), and the joints <b>34</b> may have a trapezoidal shape in a cross-sectional view in the first direction (e.g., the X direction).

The joints <b>34</b> may respectively include a support side <b>341</b> facing the bendable region <b>103</b>, and two slanted sides <b>342</b> provided at a back of the support side <b>341</b>. For example, the two slanted sides <b>342</b> may extend from the support side <b>341</b>. The joints <b>34</b> may respectively rotate with respect to two rotation shafts <b>35</b> provided on respective end portions of the support side <b>341</b>, and each joint <b>34</b> may be combined with a neighboring joint <b>34</b> with the rotation shaft <b>35</b> therebetween.

For example, the first support plate <b>31</b>, the joints <b>34</b>, and the second support plate <b>32</b> may be connected by a plurality of hinge shafts. In this case, the hinge shafts function as the rotation shafts <b>35</b>. A plurality of support sides <b>341</b> are parallel to each other in the unfolded state of the display device <b>100</b>, and are parallel to the first support plate <b>31</b> and the second support plate <b>32</b>.

The multi-joint member may also be an elastic plate with a plurality of triangular shaped grooves arranged at the back of the elastic plate and parallel to the second direction (e.g., the Y direction). In this case, an upper portion of each triangular shaped groove is bent and functions as the rotation shaft <b>35</b>.

The form varying support unit <b>33</b> is not limited to the multi-joint member, and a configuration that is switchable between the flat state and the bent state is applicable thereto. The display device <b>100</b> is in the unfolded state when the form varying support unit <b>33</b> is flat, and the display device <b>100</b> is in the folded state when the form varying support unit <b>33</b> is bent.

A rear side (e.g., bottom surface) of the bendable region <b>103</b> may or may not be attached to the form varying support unit <b>33</b>. In this case, the rear side of the bendable region <b>103</b> may contact the support side <b>341</b> of the form varying support unit <b>33</b> or may remain slightly separated from the support side <b>341</b>. This may reduce the stress applied to the bendable region <b>103</b> while the display device <b>100</b> is in the folded state.

<figref idref="DRAWINGS">FIG. 5</figref> shows a cross-sectional view of a display device with respect to a line V-V of <figref idref="DRAWINGS">FIG. 1</figref> according to an exemplary embodiment of the present invention, and <figref idref="DRAWINGS">FIG. 6</figref> shows a partial perspective view of an elastic support unit in a display device shown in <figref idref="DRAWINGS">FIG. 1</figref> according to an exemplary embodiment of the present invention.

Referring to <figref idref="DRAWINGS">FIG. 1</figref>, <figref idref="DRAWINGS">FIG. 5</figref>, and <figref idref="DRAWINGS">FIG. 6</figref>, the elastic support unit <b>40</b> includes a pair of guide lines <b>41</b> (e.g., openings in the first and second support plates <b>31</b> and <b>32</b>) provided on at least one lateral side <b>311</b> of the first support plate <b>31</b> and at least one lateral side <b>321</b> of the second support plate <b>32</b>, a pair of rolling members <b>42</b> disposed in the one pair of guide lines <b>41</b> such that the rolling members <b>42</b> may slide or rotate along the guide lines <b>41</b>, and an elastic body <b>45</b> having respective end portions fixed to the one pair of rolling members <b>42</b>.

The first support plate <b>31</b> includes two lateral sides <b>311</b> in parallel to the first direction (e.g., the X direction), and the second support plate <b>32</b> includes two lateral sides <b>321</b> in parallel to the first direction (e.g., the X direction). A pair of guide lines <b>41</b> are provided on one lateral side <b>311</b> of the first support plate <b>31</b> and one lateral side <b>321</b> of the second support plate <b>32</b> facing each other in the first direction (e.g., the X direction) with the form varying support unit <b>33</b> therebetween.

The one pair of guide lines <b>41</b> linearly extend in the first direction (e.g., the X direction), and include a first end portion P<b>1</b> provided to be closest to the form varying support unit <b>33</b> and a second end portion P<b>2</b> provided to be the most distant from the form varying support unit <b>33</b>. The one pair of guide lines <b>41</b> may include an inlet portion <b>411</b> and an internal portion <b>412</b> that is wider than the inlet portion <b>411</b>. In other words, the one pair of guide lines <b>41</b> may be a concave groove and have a T-like shape in the cross-sectional view. One pair of rolling members <b>42</b> may include a ring-shaped slider <b>43</b> received in the internal portion <b>412</b> of the guide line <b>41</b>, and a rotation pin <b>44</b> including a first end combined to the slider <b>43</b> such that the rotation pin <b>44</b> can rotate and a second end protruding outside of the guide line <b>41</b>. In an exemplary embodiment of the present invention, the slider <b>43</b> and the rotation pin <b>44</b> may have circular shapes, and the rotation pin <b>44</b> may have a diameter smaller than that of the slider <b>43</b>. The slider <b>43</b> may be inserted into the internal portion <b>412</b> of the guide line <b>41</b> with a sliding margin and may slide in a length direction of the guide line <b>41</b> (e.g., the X direction).

The slider <b>43</b> functions as a bearing for supporting rotation of the rotation pin <b>44</b>, and it may be combined with the rotation pin <b>44</b> in various ways. For example, the rotation pin <b>44</b> and the slider <b>43</b> may be combined by a protrusion-groove structure to prevent the rotation pin <b>44</b> from detaching from the slider <b>43</b>, and may be combined by loosely inserting the rotation pin <b>44</b> into the slider <b>43</b> so that the rotation pin <b>44</b> may rotate in the slider <b>43</b>. The combined structure of the rotation pin <b>44</b> and the slider <b>43</b> is not limited to the shown example.

The elastic body <b>45</b> may include various elastic members such as an elastic band or a coil spring, and respective end portions of the elastic body <b>45</b> are fixed to a pair of rotation pins <b>44</b>. For illustrative purposes, <figref idref="DRAWINGS">FIG. 1</figref> and <figref idref="DRAWINGS">FIG. 6</figref> show the elastic body <b>45</b> including a coil spring. However, the present invention is not limited thereto.

The foldable module <b>20</b> may include an elastic support unit <b>40</b> connected to one side of the panel support unit <b>30</b>, or may include a pair of elastic support units <b>40</b> connected to respective sides of the panel support unit <b>30</b>. <figref idref="DRAWINGS">FIG. 5</figref> illustrates the case in which the foldable module <b>20</b> includes a pair of elastic support units <b>40</b>. However, the present invention is not limited thereto.

A length (L) (refer to <figref idref="DRAWINGS">FIG. 3</figref>) between two first end portions P<b>1</b> provided on respective sides of the form varying support unit <b>33</b> is greater than an initial length (e.g., the length of the elastic body <b>45</b> when no tensile force is applied) of the elastic body <b>45</b>. While the display device <b>100</b> is in the unfolded state, a pair of rolling members <b>42</b> are provided on the first end portion P<b>1</b> that is provided nearest to the form varying support unit <b>33</b>, and the elastic body <b>45</b> can extend to the maximum extent. The extended elastic body <b>45</b> has an elastic restoration force to contract back to its initial side, for example.

The display device <b>100</b> according to an exemplary embodiment of the present invention may be folded by an out-folding method in which the display panel <b>10</b> is provided outside the foldable module <b>20</b> in the folded state, and an in-folding method in which the display panel <b>10</b> is provided inside the foldable module <b>20</b> in the folded state. For example, by using the out-folding method, the first region <b>101</b> of the display panel <b>10</b> may face away from the second region <b>102</b> of the display panel <b>10</b>, and by using the in-folding method, the first region <b>101</b> may face the second region <b>102</b>.

In other words, the display device <b>100</b> may have a uni-directional folding structure such that it can be folded by the out-folding method and the in-folding method, or it may have a bi-directional folding structure such that a user may bend the display device <b>100</b> by selecting one of the out-folding method and the in-folding method.

<figref idref="DRAWINGS">FIG. 7</figref> shows a side view of a display device while being folded by an out-folding method according to an exemplary embodiment of the present invention. <figref idref="DRAWINGS">FIG. 8</figref> shows a side view of a display device folded by an out-folding method according to an exemplary embodiment of the present invention.

Referring to <figref idref="DRAWINGS">FIG. 6</figref> to <figref idref="DRAWINGS">FIG. 8</figref>, the elastic body <b>45</b>, when extended to a maximum extent in the unfolded state of the display device <b>100</b>, has the elastic restoration force to contract. During the unfolded state, when the user applies a force to the display device <b>100</b> to fold the display device <b>100</b>, the force applied by the user and the elastic restoration force of the elastic body <b>45</b> are applied to the display panel <b>10</b> and the display panel <b>10</b> is quickly folded.

For example, when the user applies a force to the display device <b>100</b> to fold the display device <b>100</b>, the form varying support unit <b>33</b> and the bendable region <b>103</b> start to be bent. At this time, a pair of rolling members <b>42</b> slide away from the form varying support unit <b>33</b>, and the elastic body <b>45</b> contracts to pull the first support plate <b>31</b> and the second support plate <b>32</b> toward each other.

When the elastic body <b>45</b> contracts from the extending state, the rotation pin <b>44</b> rotates in the slider <b>43</b>, and respective end portions of the elastic body <b>45</b> may rotate. With reference to <figref idref="DRAWINGS">FIG. 7</figref> and <figref idref="DRAWINGS">FIG. 8</figref>, the rotation pin <b>44</b> combined with the first support plate <b>31</b> rotates by about 90 degrees in a clockwise direction, and the rotation pin <b>44</b> combined with the second support plate <b>32</b> rotates by about 90 degrees in a counterclockwise direction.

When the display device <b>100</b> is in the folded state, slanted sides <b>342</b> of the form varying support unit <b>33</b> touch each other, and the first support plate <b>31</b> overlaps the second support plate <b>32</b>. Further, while in the folded state, the pair of rolling members <b>42</b> are provided the most distant from the form varying support unit <b>33</b>, and the elastic body <b>45</b> is provided in parallel to the third direction (e.g., the Z direction) crossing the first direction (e.g., the X direction) and the second direction (e.g., the Y direction).

As the elastic body <b>45</b> pulls the first support plate <b>31</b> and the second support plate <b>32</b> with the elastic restoration force, the display panel <b>10</b> can be easily switched to the folded state from the unfolded state. Therefore, the user may easily fold the display device <b>100</b> without applying a strong force to the display device <b>100</b>. In other words, the force needed by a user to fold the display device <b>100</b> may be reduced because of the strength of the elastic restoration force of the elastic body <b>45</b>.

In an exemplary embodiment of the present invention, the one pair of guide lines <b>41</b> may extend in the first direction (e.g., the X direction) and may have a slight curvature or a plurality of slight curvatures. The slight curvature of the pair of guide lines <b>41</b> may also reduce the force needed by a user to fold the display device <b>100</b> and may prevent the display device <b>100</b> from folding too quickly.

<figref idref="DRAWINGS">FIG. 9</figref> shows a side view of a display device while being folded by an in-folding method according to an exemplary embodiment of the present invention. <figref idref="DRAWINGS">FIG. 10</figref> shows a side view of a display device folded by an in-folding method according to an exemplary embodiment of the present invention.

Referring to <figref idref="DRAWINGS">FIG. 6</figref>, <figref idref="DRAWINGS">FIG. 9</figref>, and <figref idref="DRAWINGS">FIG. 10</figref>, according to the in-folding method, the form varying support unit <b>33</b> is bent to form a semi-circle shape with the bendable region <b>103</b> within the semi-circle shape. In this configuration, the neighboring slanted sides <b>342</b> spread as far apart from each other as possible.

When the display device <b>100</b> is folded, a pair of rolling members <b>42</b> slide to be distant from the form varying support unit <b>33</b>, and the elastic body <b>45</b> contracts to pull the first support plate <b>31</b> and the second support plate <b>32</b> toward each other. During this process, the rotation pin <b>44</b> rotates in the slider <b>43</b> and the respective end portions of the elastic body <b>45</b> rotate.

With reference to <figref idref="DRAWINGS">FIG. 9</figref> and <figref idref="DRAWINGS">FIG. 10</figref>, the rotation pin <b>44</b> combined with the first support plate <b>31</b> may rotate by about 90 degrees or more in the counterclockwise direction, and the rotation pin <b>44</b> combined with the second support plate <b>32</b> may rotate by about 90 degrees or more in the clockwise direction. When the display device <b>100</b> is in the folded state, an end portion of the first support plate <b>31</b> that is most distant from the form varying support unit <b>33</b> and an end portion of the second support plate <b>32</b> that is most distant from the form varying support unit <b>33</b> may contact each other.

When the display device <b>100</b> is folded by the out-folding method or the in-folding method as described above, the display panel <b>10</b> may be easily switched to the folded state by the elastic restoration force of the elastic body <b>45</b>.

It is to be understood that the second end portion P<b>2</b> of the guide line <b>41</b> may be provided closer to the form varying support unit <b>33</b> than that shown in <figref idref="DRAWINGS">FIG. 1</figref>.

<figref idref="DRAWINGS">FIG. 11</figref> and <figref idref="DRAWINGS">FIG. 12</figref> show a side view of a folded state of a display device according to an exemplary embodiment of the present invention.

Referring to <figref idref="DRAWINGS">FIG. 11</figref> and <figref idref="DRAWINGS">FIG. 12</figref>, regarding the display device <b>200</b> according to an exemplary embodiment of the present invention, respective lengths of a pair of guide lines <b>41</b> may be substantially half the length of the respective lateral sides of the first support plate <b>31</b> and the second support plate <b>32</b>. A position of the first end portion P<b>1</b> of the guide line <b>41</b> corresponds to that shown in <figref idref="DRAWINGS">FIG. 1</figref>, and a position of the second end portion P<b>21</b> is provided nearer the form varying support unit <b>33</b> than that shown in <figref idref="DRAWINGS">FIG. 1</figref>.

When the display device <b>200</b> of <figref idref="DRAWINGS">FIGS. 11 and 12</figref> is switched to the folded state from the unfolded state, the first support plate <b>31</b> and the second support plate <b>32</b> may touch each other, and thus, the folding operation may be finished before the respective end portions of the elastic body <b>45</b> reach the second end portion P<b>2</b> of the guide line <b>41</b> shown in <figref idref="DRAWINGS">FIG. 1</figref>.

Regarding the display device <b>200</b> shown, for example, in <figref idref="DRAWINGS">FIGS. 11 and 12</figref>, when the folding operation is finished, the second end portion P<b>21</b> of the guide line <b>41</b> may correspond to the position of the end portion of the elastic body <b>45</b> or may be provided a little further from the form varying support unit <b>33</b>.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be apparent to those of ordinary skill in the art that various changes in form and detail may be made thereto without departing from the spirit and scope of the present invention as defined by the following claims.